<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    const  Student = {
        num:10,
        setNum(newNum){
            if(this.num<newNum){
                this.num = newNum;
            }else{
                throw new Error("补习班人数太少不开班")
            }

        },
        getNum(){
            return `目前在读人数${this.num}`;
        }
    }

    Student.setNum(40);

    var num = Student.getNum()
    console.log(num);

</script>
</html>